Liner for gas turbine engine

ABSTRACT

An embodiment of a gas turbine engine having a liner and casing is disclosed. The liner is disposed between the casing and a rotatable turbomachinery component. In one form, the rotatable turbomachinery component is a turbofan engine. The liner can be thin relative to a distance between the liner and the casing. Protrusions can be used between the liner and the casing. The protrusions can be a rib and can extend from the casing or the liner. An insert, such as an abradable surface, can be used with the liner. A filler can be used in the space between the liner and the casing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 61/767,102, filed 20 Feb. 2013, the disclosure ofwhich is now expressly incorporated herein by reference.

TECHNICAL FIELD

The present disclosure generally relates to liner members for gasturbine engines. More particularly, but not exclusively, the presentdisclosure relates to configurations and orientations of liner membersrelative to casings of gas turbine engines.

BACKGROUND

Providing mechanisms to contend with blade out events, such as fan bladeout events (FBO), remains an area of interest. Some liner systems employhoneycomb liners which can be used in the event of a blade rub or ablade out condition and, in these embodiments, a low density honeycombcan be used on the backside of an abradable lining that includes anepoxy filled honeycomb. Gas turbine engines can use these linersdirectly bonded to the inside of the fan case or in the form of a set ofcassettes that are bolted into place. Fillers and/or sealants can beused between liner segments and at liner to casing interfaces. Someexisting systems have various shortcomings relative to certainapplications. Accordingly, there remains a need for furthercontributions in this area of technology.

SUMMARY

One embodiment of the present disclosure is a unique liner for a gasturbine engine. Other embodiments include apparatuses, systems, devices,hardware, methods, and combinations for liner systems. Furtherembodiments, forms, features, aspects, benefits, and advantages of thepresent application shall become apparent from the description andfigures provided herewith.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 discloses one embodiment of a gas turbine engine;

FIG. 2 discloses an embodiment of a liner and casing;

FIG. 3 discloses an embodiment of a liner and casing;

FIG. 4 discloses an embodiment of a liner and casing;

FIG. 5 discloses an embodiment of a liner and casing; and

FIG. 6 discloses an embodiment of a liner and casing.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

For the purposes of promoting an understanding of the principles of thedisclosure, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of thedisclosure is thereby intended. Any alterations and furthermodifications in the described embodiments, and any further applicationsof the principles of the disclosure as described herein are contemplatedas would normally occur to one skilled in the art to which thedisclosure relates.

With reference to FIG. 1, a gas turbine engine 50 is illustrated havinga compressor 52, combustor 54, and turbine 56 which together can be usedto produce a useful power. Generally speaking, a working fluid such asair enters the gas turbine engine 50 whereupon it is compressed throughaction of the compressor before being mixed with a fuel and combusted inthe combustor 54. The turbine 56 is arranged to receive a flow from thecombustor 54 and extract useful work from the flow. The gas turbineengine can be used to provide power to, for example, an aircraft. Asused herein, the term “aircraft” includes, but is not limited to,helicopters, airplanes, unmanned space vehicles, fixed wing vehicles,variable wing vehicles, rotary wing vehicles, unmanned combat aerialvehicles, tailless aircraft, hover crafts, and other airborne and/orextraterrestrial (spacecraft) vehicles. Further, the present disclosuresare contemplated for utilization in other applications that may not becoupled with an aircraft such as, for example, industrial applications,power generation, pumping sets, naval propulsion, weapon systems,security systems, perimeter defense/security systems, and the like knownto one of ordinary skill in the art.

Turning now to FIG. 2, an embodiment of the gas turbine engine 50 isshown wherein a turbomachinery component in the form of a fan section 58of a turbofan engine is illustrated. A pressure of a flow stream 60 ischanged via operation of a fan 62 before the flow stream is splitbetween a core flow 64 and bypass flow 66. A casing 68 and a member 70forming a liner surface (hereafter liner 70 whether or not the member isa single construction, unitary component, layered assembly of parts,etc. as is described further herein) are used near the fan 62 and areshaped to be useful during a Fan Blade Out (FBO) condition in which aportion of the fan 62 may penetrate the liner 70 and be contained by thecasing 68. The casing 68 includes a portion 72 directed away from a flowpath through the fan section 58 and the liner 70 is situated between thecasing 68 and the flow path. The liner 70 forms a flow path surface overwhich the flow stream is conveyed by operation of the gas turbine engine50. The portion 72 directed away from the flow path can take a varietyof forms such as the c-shape disclosed in the illustrated embodiment,but other configurations of the recess that is formed are alsocontemplated herein.

Turning now to FIG. 3, a volume 74 is formed between the liner 70 andthe casing that in some forms can be substantially annular in shape. Thevolume 74 can have substantially the same orientation/size/etc.circumferentially around the gas turbine engine 50, but some variationsare contemplated herein. For example, some structure(s) can be locatedwithin the volume 74 for any variety of purposes. The volume 74generally has a depth d that in some embodiments, such as theillustrated embodiment, can vary from a forward end 76 to an aft end 78of the volume 74. The depth d is generally as large as or larger than athickness t of the liner 70, but smaller ranges are also contemplated inany of the various embodiments herein. In some forms the depth d isseveral times the size of the liner thickness t. In those cases wherethe depth d varies widely between the forward end 76 and aft end 78,and/or in those cases where the thickness t varies widely between theforward end 76 and aft end 78, the depth d can be as large or largerthan the size of the liner thickness t over a relatively large range ofthe axial length of the volume 74, and/or than the size of the thicknesst in the area around the fan 62. Such a characteristic can sometimes bereferred to as a base thickness. To set forth just a few non-limitingexamples, the depth d can be twice as large as or larger than thethickness t, where such larger variation can be any multiple, orintermediate multiple.

Lugs 80 can be provided to mount the liner 70 to the casing 68. The lugs80 can be formed in the casing 68 and in some forms are intermediatestructure coupled to the casing 68. The lugs 80 can take any suitableform, including flanges, etc., that are used to provide a supportingsurface to which the liner 70 is affixed. The lugs 80 can becircumferentially formed surfaces, and, in some embodiments, the lugs 80can be localized features at select circumferential locations. Theforward and aft lugs 80 can take a similar form (integral with casing,coupled with casing, flanges, etc.), but in some embodiments the forwardand aft lugs 80 can be different.

The liner 70 can be affixed to the casing 68 and/or the lugs 80 usingany variety of techniques. For example, the liner 70 can be affixedrelative to the casing 68 using mechanical fasteners such as bolts,screws, rivets, etc., and in some forms can be bonded to the casing 68using chemical and/or metallurgical bonding techniques, such as adhesionbonding or welding, to set forth just a few non-limiting examples ofaffixing the liner 70.

The manner in which the liner 70 is affixed, and alternatively and/oradditionally the construction of the liner 70, can determine the mannerin which the liner 70 reacts when contacted by the fan 62. It isgenerally contemplated that the liner 70 reacts by moving and/orremoving at least a portion such that a space is created as a result ofa trajectory of the fan 62. Such a space can be permanently formed suchas, for example, when the liner 70 yields to a reaction with the fan 62.For example, the liner 70 can react to contact from the fan 62 by beingfrangible. In this example such a reaction can be determined by theconstruction of the liner 70, such as, for example, whether it isconstructed of a single material having ductile properties. In someembodiments, the liner 70 can react by rupturing at a contact area withthe fan 62, and in some forms can additionally and/or alternativelyseparate at one or more points where the liner 70 is affixed. In stillfurther forms, the liner 70 can react by separating from the casing 68and/or lugs 80 in lieu of permanently yielding. In still further forms,the liner 70 can be separated from the casing 68 through a combinationof yielding and separating. Not all portions of the liner 70 need reactwhen the fan 62 makes contact. For example, some portion of the liner 70can remain behind after a contact. In short, any variety of dynamicimpact reactions is contemplated.

The liner 70 of the illustrated embodiment generally extends around thecircumferential annular flow space of the turbofan engine. The liner 70can be segmented such that a series of liner constructions aredistributed around the fan 62. In those embodiments in which segmentsare used, not all segments need react to a blade contact. For example,when a Fan Blade Out occurrence causes a rotor imbalance in which thefan 62 orbits about an axis, certain circumferential locations of theliner 70 can react with the fan while other circumferential locations donot react with the fan. The segments can be similarly shaped, but insome embodiments not all segments need be similar to each other. A seal,such as a filler or sealant, can be used between circumferentialsegments. Additionally and/or alternatively, a seal can be used in theforward and aft portions of the liner 70.

In one non-limiting embodiment, the volume 74 between the liner and thecasing can be substantially empty. For example, the space can provide anannular volume of air. In some embodiments the volume 74 can besegregated in some fashion. In those embodiments, the segregatedcompartments can be substantially empty of any materials with theexception of air or other working fluid. In still further non-limitingembodiments, the volume 74 can include a low-density filler that couldbe used in some applications to increase stiffness and dampening. Such afiller could be located at one or more circumferential locations in thevolume 74, or alternatively be located throughout the volume 74distributed around the fan 62.

The liner 70 can be constructed in a variety of manners. For example,the liner 70 can be constructed as a single article or as an articlethat has portions fastened/bonded/etc. to one another. Such an articlehaving portions connected to one another can take the form of a layeredcomposition. The liner 70 can be cast, stamped, molded, or made in acomposite construction. The liner 70, furthermore, can be made of one ormore materials such as metallic, plastic, composite, etc. In short, theliner 70 can take on any variety of constructions.

Turning now to FIG. 4, one non-limiting embodiment is shown of a liner70 having an insert 82 which can be used in the event of a rubbing eventwith the fan 62. Such an insert 82 can be an abradable material appliedto the liner 70 using a variety of techniques whether mechanicallyfastened, cast, chemically or metallurgically bonded, spray coated, etc.The insert 82 can be any variety of depths and can extend any distancebetween the forward end 76 and aft end 78. As shown in the illustratedembodiment, the insert 82 extends only partially between the forward end76 and aft end 78. In some forms the insert 82 is located in the area ofthe fan 62.

One or more protrusion(s) 84 can extend between the casing 68 and theliner 70, two non-limiting examples of which are shown in FIGS. 5 and 6.The protrusions 84 can take a variety of shapes, sizes, orientations,etc. and, in the illustrated embodiments, are shown generally as ribsthat extend generally along a line. The protrusions 84 can be integrallyformed with the structure from which it extends, but in some forms canbe fastened using any variety of techniques. Furthermore, any number ofprotrusions 84 can be used in any given liner 70. FIG. 5 illustrates anumber or protrusions 84 extending from the liner 70 toward the casing68 and in which a gap is formed between the end of one or moreprotrusions 84 and the casing 68. The gaps can be, but need not be, thesame for each of the protrusions 84. In some forms the gaps may not bepresent. A frictional interface can be used in some forms. FIG. 6illustrates protrusions 84 extending from the casing 68 and in which nogap is present with respect to the liner 70. One or more gaps betweenthe liner 70 and protrusions 84 could be formed in some embodiments.

In those embodiments that contain one or more protrusions from thebackside of the liner 70, the thickness t discussed above in regard tothe depth d of the volume 74 can be considered the thickness t on eitherside of the protrusion(s). In this way the liner 70 can be said to havea base from which the protrusions extend, where the base includes thethickness t. In those embodiments where the thickness t varies over thelength of the liner 70, the protrusions can extend from locations otherthan the base. For example, the thickness t between the upstream end anddownstream end of the liner 70 can vary, but generally, with theexception of intermediate structures such as the protrusions 84, issubstantially less than the depth d of the volume 74 created between theliner 70 and the casing 68 as discussed herein.

The volume 74 formed between the liner 70 and the casing 68 can beconsidered the volume between the casing and the liner 70, whether ornot the volume 74 includes a low density filler, etc. It will beunderstood that in those embodiments including protrusions 84, the depthd of the volume 74 is generally the depth associated between the casing68 and the liner 70, and not the minimal distance, such as the gap shownin FIG. 5, between the protrusions 84 and the casing 68.

Any of the various embodiments disclosed herein can be combined withother embodiments. For example, the insert 82 can be used with any ofthe various embodiments. For that matter, the protrusions 84 can be usedin any of the various embodiments. Other combinations are alsocontemplated herein.

One aspect of the present application provides an apparatus comprising agas turbine engine having a casing and a flow path located radiallyinward of the casing within which is disposed a rotatable turbomachinerycomponent. The flow path is bounded by a construction that provides aliner surface located between the rotatable turbomachinery component andthe casing. The construction has a base thickness between a flow pathside and a non-flow path side which is smaller than an offset betweenthe construction and the casing. The offset is free of the construction.The construction that provides the liner surface forms a flow pathsurface during a nominal mode of operation of the rotatableturbomachinery component. The construction that provides the linersurface is constructed to be sacrificial during an off-nominal mode ofoperation of the rotatable turbomachinery component such that a portionof the turbomachinery component can penetrate into an area free from theconstruction.

A feature of the present application provides wherein the rotatableturbomachinery component is a fan, and wherein an annular liner isformed that is constructed from a plurality of construction segments.Another feature of the present application provides wherein theconstruction that provides the liner surface is a single article thatforms the flow path surface and is substantially free of internal voids.

Yet another feature of the present application provides wherein theconstruction includes a base portion and an abradable material adjacentthe base portion. Still another feature of the present applicationprovides wherein the off-nominal mode of operation includes an orbitingmotion of the turbomachinery component, and wherein the gas turbineengine also including protrusions disposed in the area free from theconstruction.

Yet still another feature of the present application provides whereinthe construction that provides the liner surface includes theprotrusions. Still yet another feature of the present applicationprovides wherein the area free from the construction includes a lowdensity filler material. A further feature of the present applicationprovides wherein the construction includes a plurality of materials.

Another aspect of the present application provides an apparatuscomprising a gas turbine engine including a fan section having arotatable fan blade portion structured to change a pressure of a workingfluid flowing through a flow path of the fan section, a casing radiallyoutward of the rotatable fan blade portion and having a shape thediverges from the flow path of the fan section, and a component having aliner surface radially inward from the casing to separate the casingfrom the rotatable fan blade portion. The component is offset from thecasing to create a space free of a honeycomb structure intermediate theliner and the casing. The space is larger than a thickness of thecomponent axially coincident with the rotatable fan blade portion.

A feature of the present application provides wherein the component isfixed relative to the casing through one of mechanical fastening orbeing bonded in place. Another feature of the present applicationprovides wherein a coupling interface between the component and thecasing is structured to fail and release the component when the fanblade portion contacts the component.

Yet another feature of the present application provides wherein thecomponent is stamped sheet metal. Still another feature of the presentapplication provides wherein the component is molded, and wherein thecomponent is one of plastic and composite.

Yet still another feature of the present application provides whereinthe component includes a solidity that substantially lacks internalvoids. A further feature of the present application provides whereinliner includes a base plate and which further includes elongate portionsthat extend from between the back of the component and the casing. Astill further feature of the present application provides wherein thespace free of a honeycomb structure is an empty space.

Yet another aspect of the present application provides an apparatuscomprising a gas turbine engine having a compressor rotatingly coupledwith a turbine and a casing configured to enclose a bladed component ofthe gas turbine engine, and reaction means for ingressing a portion ofthe bladed component into a space formed between the casing and thereaction means. The reaction means is disposed between the casing andthe bladed component to create a non-flow path volume. The reactionmeans having a predominate thickness extending between an upstream endand a downstream end. The non-flow path volume having a depth measuredbetween the casing to the predominate thickness. The thickness of thereaction means is substantially smaller than the depth measured betweenthe casing and the predominate thickness.

Still yet another aspect of the present application provides a methodcomprising a number of operations. The operations including rotating abladed member of a gas turbine engine having a casing and a linersituated between the casing and the bladed member to create an areatherebetween, the bladed member travelling along a nominal arc ofrotation, impacting at least a portion of the bladed member with a linerlocated between the bladed member and a casing of the gas turbineengine, and reacting the liner with the portion of the bladed member toexpose a volume formed by a placement of the liner relative to thecasing, the liner providing an offset flow path surface for a workingfluid from the casing.

A feature of the present application further includes penetrating theliner with the portion of the bladed member. Another feature of thepresent application provides wherein the reacting includes breaking theliner.

Yet another feature of the present application provides wherein thebreaking includes removing at least a portion of the liner. Stillanother feature of the present application provides wherein the removingincludes breaching a manner in which the liner is affixed relative tothe casing. Yet still another feature of the present applicationprovides wherein the breaching includes destroying a bond between theliner and the casing.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiments have been shown and described and thatall changes and modifications that come within the spirit of thedisclosures are desired to be protected. It should be understood thatwhile the use of words such as preferable, preferably, preferred or morepreferred utilized in the description above indicate that the feature sodescribed may be more desirable, it nonetheless may not be necessary andembodiments lacking the same may be contemplated as within the scope ofthe disclosure, the scope being defined by the claims that follow. Inreading the claims, it is intended that when words such as “a,” “an,”“at least one,” or “at least one portion” are used there is no intentionto limit the claim to only one item unless specifically stated to thecontrary in the claim. When the language “at least a portion” and/or “aportion” is used the item can include a portion and/or the entire itemunless specifically stated to the contrary.

What is claimed is:
 1. An apparatus comprising: a gas turbine enginehaving a casing and a flow path located radially inward of the casingwithin which is disposed a rotatable turbomachinery component, the flowpath bounded by a construction that provides a liner surface locatedbetween the rotatable turbomachinery component and the casing, theconstruction having a base thickness between a flow path side and anon-flow path side which is smaller than an offset between theconstruction and the casing, the offset being free of the construction;wherein the construction that provides the liner surface forms a flowpath surface during a nominal mode of operation of the rotatableturbomachinery component, and wherein the construction that provides theliner surface is constructed to be sacrificial during an off-nominalmode of operation of the rotatable turbomachinery component such that aportion of the turbomachinery component can penetrate into an area freefrom the construction.
 2. The apparatus of claim 1, wherein therotatable turbomachinery component is a fan, and wherein an annularliner is formed that is constructed from a plurality of constructionsegments, and wherein the construction that provides the liner surfaceis a single article that forms the flow path surface and issubstantially free of internal voids.
 3. The apparatus of claim 1,wherein the construction includes a base portion and an abradablematerial adjacent the base portion.
 4. The apparatus of claim 1, whereinthe off-nominal mode of operation includes an orbiting motion of theturbomachinery component, and wherein the gas turbine engine alsoincludes protrusions disposed in the area free from the construction. 5.The apparatus of claim 4, wherein the construction that provides theliner surface includes the protrusions.
 6. The apparatus of claim 1,wherein the area free from the construction includes a low densityfiller material.
 7. The apparatus of claim 1, wherein the constructionincludes a plurality of materials.
 8. An apparatus comprising: a gasturbine engine including a fan section having a rotatable fan bladeportion structured to change a pressure of a working fluid flowingthrough a flow path of the fan section; a casing radially outward of therotatable fan blade portion and having a shape that diverges from theflow path of the fan section; and a component having a liner surfaceradially inward from the casing to separate the casing from therotatable fan blade portion, the component offset from the casing tocreate a space free of a honeycomb structure intermediate the liner andthe casing, the space being larger than a thickness of the componentaxially coincident with the rotatable fan blade portion.
 9. Theapparatus of claim 8, wherein the component is fixed relative to thecasing through one of mechanical fastening or being bonded in place. 10.The apparatus of claim 8, wherein a coupling interface between thecomponent and the casing is structured to fail and release the componentwhen the fan blade portion contacts the component.
 11. The apparatus ofclaim 8, wherein the component is stamped sheet metal.
 12. The apparatusof claim 8, wherein the component is molded, and wherein the componentis one of plastic and composite.
 13. The apparatus of claim 8, whereinthe component includes a solidity that substantially lacks internalvoids.
 14. The apparatus of claim 8, wherein the liner includes a baseplate and which further includes elongate portions that extend frombetween a back of the component and the casing.
 15. The apparatus ofclaim 8, wherein the space free of a honeycomb structure is an emptyspace.
 16. The apparatus of claim 8 further comprising a compressorrotatingly coupled with a turbine and wherein the casing is configuredto enclose the fan blade; and reaction means for ingressing a portion ofthe fan blade into a space formed between the casing and the reactionmeans, the reaction means disposed between the casing and the fan bladeto create a non-flow path volume, the reaction means having apredominate thickness extending between an upstream end and a downstreamend, the non-flow path volume having a depth measured between the casingto the predominate thickness, and wherein the thickness of the reactionmeans is substantially smaller than the depth measured between thecasing and the predominate thickness.
 17. A method comprising: rotatinga bladed member of a gas turbine engine having a casing and a linersituated between the casing and the bladed member to create an areatherebetween, the bladed member travelling along a nominal arc ofrotation; impacting at least a portion of the bladed member with a linerlocated between the bladed member and a casing of the gas turbineengine; and reacting the liner with the portion of the bladed member toexpose a volume formed by a placement of the liner relative to thecasing, the liner providing an offset flow path surface for a workingfluid from the casing.
 18. The method of claim 17, which furtherincludes penetrating the liner with the portion of the bladed member.19. The method of claim 17, wherein the reacting includes breaking theliner, and wherein the breaking includes removing at least a portion ofthe liner.
 20. The method of claim 19 wherein the removing includesbreaching a manner in which the liner is affixed relative to the casing,and wherein the breaching includes destroying a bond between the linerand the casing.